class NullCoalesce in Drupal 8

Provides a Null Coalesce process plugin.

Given a set of values provided to the plugin, the plugin will return the first non-null value.

Available configuration keys:

• source: The input array.
• default_value: (optional) The value to return if all values are NULL. if not provided, NULL is returned if all values are NULL.

Example: Given source keys of foo, bar, and baz:

process_key: plugin: null_coalesce source:

• foo
• bar
• baz

This plugin will return the equivalent of `foo ?? bar ?? baz`

Plugin annotation

@MigrateProcessPlugin(
  id = "null_coalesce"
)

Hierarchy

• class \Drupal\Component\Plugin\PluginBase implements DerivativeInspectionInterface, PluginInspectionInterface
  • class \Drupal\Core\Plugin\PluginBase uses DependencySerializationTrait, MessengerTrait, StringTranslationTrait
    • class \Drupal\migrate\ProcessPluginBase implements MigrateProcessInterface
      • class \Drupal\migrate\Plugin\migrate\process\NullCoalesce

1 file declares its use of NullCoalesce

NullCoalesceTest.php in core/modules/migrate/tests/src/Unit/process/NullCoalesceTest.php

File

core/modules/migrate/src/Plugin/migrate/process/NullCoalesce.php, line 37

Namespace

Drupal\migrate\Plugin\migrate\process

class NullCoalesce extends ProcessPluginBase {

  /**
   * {@inheritdoc}
   */
  public function transform($value, MigrateExecutableInterface $migrate_executable, Row $row, $destination_property) {
    if (!is_array($value)) {
      throw new MigrateException("The input value should be an array.");
    }
    foreach ($value as $val) {
      if (NULL !== $val) {
        return $val;
      }
    }
    if (isset($this->configuration['default_value'])) {
      return $this->configuration['default_value'];
    }
    return NULL;
  }

}

Members

Name	Modifiers	Type	Description	Overrides
DependencySerializationTrait::$_entityStorages	protected	property	An array of entity type IDs keyed by the property name of their storages.
DependencySerializationTrait::$_serviceIds	protected	property	An array of service IDs keyed by property name used for serialization.
DependencySerializationTrait::__sleep	public	function		1
DependencySerializationTrait::__wakeup	public	function		2
MessengerTrait::$messenger	protected	property	The messenger.	29
MessengerTrait::messenger	public	function	Gets the messenger.	29
MessengerTrait::setMessenger	public	function	Sets the messenger.
NullCoalesce::transform	public	function	Performs the associated process. Overrides ProcessPluginBase::transform
PluginBase::$configuration	protected	property	Configuration information passed into the plugin.	1
PluginBase::$pluginDefinition	protected	property	The plugin implementation definition.	1
PluginBase::$pluginId	protected	property	The plugin_id.
PluginBase::DERIVATIVE_SEPARATOR		constant	A string which is used to separate base plugin IDs from the derivative ID.
PluginBase::getBaseId	public	function	Gets the base_plugin_id of the plugin instance. Overrides DerivativeInspectionInterface::getBaseId
PluginBase::getDerivativeId	public	function	Gets the derivative_id of the plugin instance. Overrides DerivativeInspectionInterface::getDerivativeId
PluginBase::getPluginDefinition	public	function	Gets the definition of the plugin implementation. Overrides PluginInspectionInterface::getPluginDefinition	3
PluginBase::getPluginId	public	function	Gets the plugin_id of the plugin instance. Overrides PluginInspectionInterface::getPluginId
PluginBase::isConfigurable	public	function	Determines if the plugin is configurable.
PluginBase::__construct	public	function	Constructs a \Drupal\Component\Plugin\PluginBase object.	92
ProcessPluginBase::multiple	public	function	Indicates whether the returned value requires multiple handling. Overrides MigrateProcessInterface::multiple	3
StringTranslationTrait::$stringTranslation	protected	property	The string translation service.	1
StringTranslationTrait::formatPlural	protected	function	Formats a string containing a count of items.
StringTranslationTrait::getNumberOfPlurals	protected	function	Returns the number of plurals supported by a given language.
StringTranslationTrait::getStringTranslation	protected	function	Gets the string translation service.
StringTranslationTrait::setStringTranslation	public	function	Sets the string translation service to use.	2
StringTranslationTrait::t	protected	function	Translates a string to the current language or to a given language.